Does this not do what you want:
»www.yaesu.com/downloadFile.cfm?F ··· on%2Fpdf
You may desire to delete the memories (except the Memory Channel 1 and Home Channel).
The procedure for deleting a channel is quite simple.
1. Press the [V/M(PRI)] key, if needed, to enter the MR mode.
2. Press and hold in the [F/W] key for one second, then rotate the DIAL knob to select
the memory channel to be deleted.
3. Press the [HM/RV] key momentarily. The display will revert to memory channel #1.
The previously-selected memory will be deleted.
Important Notice! Once deleted, the channel data cannot be recovered!